New tsunami hazard maps highlight threat facing seven California counties — even Napa, where the quake didn’t hit
The U.S. Geological Survey has created new maps showing the threat posed by the California earthquake on the coast. (U.S. Geological Survey)
The new threat maps show the extent of damage caused by the deadly earthquake.
In Napa County, the quake didn’t reach the city, but the threat is still high.
For the first time, the U.S. Geological Survey has created “zone-by-zone hazard maps” of the California coastline with a six-centimeter resolution for seven counties: Alameda, Contra Costa, Marin, Napa, San Mateo, San Diego and Santa Cruz.
The maps have a six-centimeter resolution so they can be overlaid on maps to show the extent of damage at the ground level.
The data are intended to help coastal communities prepare for earthquakes.
“When the initial tsunami hazard maps were created, they were developed to guide the deployment of emergency equipment, such as coastal warning systems, early warning systems and tsunami warning platforms,” said Megan Treadway, a geoscience communications specialist for the USGS Hazards & Geomechanics (H&G) program. “Now with the new hazard maps, they will be used to guide how we think about building new structures in the future.”
The earthquake — which struck with a magnitude of 7.9 on the Richter scale — was the largest ever to strike on the U.S. West Coast and one of the largest in California’s recorded history. It killed more than 180 people, destroyed or damaged more than 5,100 buildings, including 2,300 in Marin, 300 in San Mateo and 400 in San Diego. The death toll is now the highest by magnitude in the history of the state.
The new hazard maps give a first look at how the earthquake changed the nature of the coast as it extended from San Francisco Bay to the Pacific Ocean.
In Napa County, which is in the heart of wine country, the earthquake didn’t cause any significant damage.
Some businesses were able to open early and some people started drinking before cell service was restored about an hour after the quake.
“I was on my phone and I heard some screams,